Some recreational vehicles, such as all-terrain vehicles (ATV's), utility vehicles, motorcycles, etc., include a continuously variable transmission (CVT). In these vehicles, an actuator adjusts the position of one of the primary and secondary clutches of the CVT. The thrust requirement of the actuator for moving the clutch is generally dependent on the sliding friction between the movable sheave and the sliding coupling.
Available space is often limited around the CVT for placing the components of the actuator assembly. As such, actuator components having a large package size are often difficult to place in close proximity to the CVT. Further, the removal of some or all of the actuator components is often required when replacing the CVT belt.
A starting clutch is sometimes used to engage the CVT. The starting clutch is positioned at the driven or secondary clutch of the CVT to engage the secondary clutch when the CVT is in a low gear ratio condition. Due to the low speeds and high torques of the secondary clutch when the starting clutch engages the secondary clutch, the starting clutch is generally large in size.
In some recreational vehicles with CVT's, such as snowmobiles, the electrical system does not include a battery. As such, the rotational motion of the engine is used to generate power for the vehicle. In these vehicles, or in vehicles that experience a sudden power loss, the clutch assembly of the CVT may require a manual reset to a home position prior to starting the vehicle.
In an exemplary embodiment of the present disclosure, a recreational vehicle is provided including a chassis and a drive train. The drive train includes an engine supported by the chassis, a continuously variable transmission driven by the engine, and a ground engaging mechanism configured to support the chassis. The continuously variable transmission includes a first clutch and a second clutch. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The vehicle includes a suspension system coupled between the chassis and the ground engaging mechanism. The vehicle further includes at least one of a speed sensor and a suspension sensor. The speed sensor is configured to detect a speed of the drive train, and the suspension sensor is configured to detect a height of the suspension system. The vehicle further includes a controller configured to control the first clutch of the continuously variable transmission. The controller is operative to detect an airborne state of the vehicle based on at least one of the detected speed of the drive train and the detected height of the suspension system. The controller is operative to adjust the first clutch upon a detection of the airborne state to reduce an acceleration of the drive train.
In another exemplary embodiment of the present disclosure, a method of controlling a continuously variable transmission of a vehicle is provided. The method includes providing a vehicle including a chassis, a suspension system, and a drive train. The drive train includes an engine, a continuously variable transmission driven by the engine, and a ground engaging mechanism configured to support the chassis. The continuously variable transmission includes a first clutch and a second clutch. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The method includes detecting a speed of the drive train with a speed sensor and detecting an airborne state of the vehicle based on at least one of an acceleration of the drive train and a height of the suspension system. The acceleration is determined based on the detected speed of the vehicle. The method further includes adjusting the first clutch of the continuously variable transmission upon detection of the airborne state of the vehicle to reduce the acceleration of the drive train.
In yet another exemplary embodiment of the present disclosure, a method of controlling a continuously variable transmission of a vehicle is provided. The method includes providing a vehicle having a continuously variable transmission, an actuator coupled to the continuously variable transmission, and an auxiliary power connector configured to route electrical power from an external power supply to the actuator. The continuously variable transmission includes a first clutch, a second clutch, and a belt coupled to the first and second clutches. The actuator is configured to move the first clutch to adjust a gear ratio of the continuously variable transmission. The method includes detecting a connection of the external power supply to the auxiliary power connector. The method further includes routing to the actuator electrical power from the auxiliary power connector upon detecting the external power supply. The method further includes controlling the actuator with the electrical power to move the first clutch to a home position.
In still another exemplary embodiment of the present disclosure, a recreational vehicle is provided including a chassis and a drive train. The drive train includes an engine supported by the chassis, a continuously variable transmission driven by the engine, and a ground engaging mechanism configured to support the chassis. The continuously variable transmission includes a first clutch, a second clutch, and a belt coupled to the first and second clutches. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The vehicle further includes an actuator coupled to the continuously variable transmission for adjusting the first clutch. The vehicle further includes an auxiliary power connector configured to route electrical power to the actuator from an external power source. The vehicle further includes a controller operative to control routing of the electrical power from the external power source to the actuator to power the actuator. The controller is operative to detect a connection of the external power source to the auxiliary power connector and to control the actuator with the electrical power to move the first clutch to a home position upon detection of the external power supply.
In another exemplary embodiment of the present disclosure, a method of controlling a continuously variable transmission of a vehicle is provided. The method includes providing a vehicle having a continuously variable transmission, an actuator coupled to the continuously variable transmission, a power generator configured to provide electrical power to the vehicle during operation of the vehicle, and an energy storage device. The continuously variable transmission includes a first clutch and a second clutch. The actuator is configured to adjust a position of the first clutch to modulate a gear ratio of the continuously variable transmission. The method includes controlling the first clutch of the continuously variable transmission with the electrical power provided with the power generator. The method further includes charging the energy storage device with the electrical power provided with the power generator during operation of the vehicle while the energy storage device is electrically decoupled from the actuator. The method further includes detecting a loss of electrical power from the power generator. The method further includes routing electrical power from the energy storage device to the actuator to move the first clutch to a home position upon detecting the loss of electrical power from the power generator.
In yet another exemplary embodiment of the present disclosure, a recreational vehicle is provided that includes a chassis and a drive train. The drive train includes an engine supported by the chassis, a continuously variable transmission driven by the engine, and a ground engaging mechanism configured to support the chassis. The continuously variable transmission includes a first clutch, a second clutch, and a belt coupled to the first and second clutches. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The vehicle includes a power generator coupled to and driven by the engine for providing electrical power to the vehicle. The vehicle includes an energy storage device configured to store electrical power provided by the power generator. The vehicle further includes at least one controller operative to route power from the power generator to the actuator to control the position of first clutch of the continuously variable transmission during vehicle operation. The at least one controller is further operative to route electrical power stored at the energy storage device to the actuator to move the first clutch to a home position upon detection by the at least one controller of a loss of electrical power from the power generator.
In still another exemplary embodiment of the present disclosure, a method of controlling a continuously variable transmission of a vehicle is provided. The vehicle includes an engine operative to drive the continuously variable transmission. The continuously variable transmission of the vehicle includes a first clutch and a second clutch. The first clutch is moveable by an actuator to modulate a gear ratio of the continuously variable transmission. The method includes determining a speed of the engine of the vehicle, detecting a throttle demand, and determining a clutch control variable based on an operator input device. The method includes calculating a target engine speed based on the throttle demand and the clutch control variable. The method further includes calculating a target position of the first clutch of the continuously variable transmission based on the calculated target engine speed and the determined speed of the engine.
In another exemplary embodiment of the present disclosure, a vehicle is provided that includes a chassis, a ground engaging mechanism configured to support the chassis, an engine supported by the chassis, and a continuously variable transmission driven by the engine. The continuously variable transmission includes a first clutch, a second clutch, and a belt coupled to the first and second clutches. The first clutch is adjustable with an actuator to modulate a gear ratio of the continuously variable transmission. The vehicle includes a throttle valve configured to regulate a speed of the engine. The vehicle includes at least one controller including engine control logic operative to control a position of the throttle valve and transmission control logic operative to control a position of the first clutch of the continuously variable transmission. The vehicle further includes an engine speed sensor in communication with the at least one controller for detecting a speed of the engine. The vehicle further includes a throttle operator device moveable by an operator. The throttle operator device includes a position sensor in communication with the at least one controller, and the position sensor is configured to detect a position of the throttle operator. The vehicle further includes an operator input device in communication with the at least one controller and configured to adjust a clutch control variable provided to the at least one controller. The transmission control logic is operative to calculate a target engine speed based on the clutch control variable and the position of the throttle operator device. The transmission control logic is operative to calculate a target position of the first clutch of the continuously variable transmission based on the target engine speed and the detected engine speed.
In yet another exemplary embodiment of the present disclosure, a method of controlling a continuously variable transmission of a vehicle is provided. The vehicle includes an engine operative to drive the continuously variable transmission. The method includes controlling, by transmission control logic, a first clutch of the continuously variable transmission of the vehicle to an initial fixed position in a manual mode of operation. The continuously variable transmission includes the first clutch, a second clutch, and a belt coupled to the first and second clutches. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The first clutch of the continuously variable transmission in the manual mode of operation is adjustable between a plurality of discrete fixed positions based on shift requests initiated with a shift request device. The method further includes receiving a shift request identifying a target fixed position of the first clutch of the continuously variable transmission. The method further includes shifting the continuously variable transmission from the initial fixed position to the target fixed position. The method further includes initiating a torque reduction of the engine during the shifting to reduce a torque generated by the engine. At least one of a magnitude and a duration of the torque reduction is adjustable based on an operator input device.
In still another exemplary embodiment of the present disclosure, a vehicle is provided that includes a chassis, a ground engaging mechanism configured to support the chassis, an engine supported by the chassis, and a continuously variable transmission driven by the engine. The continuously variable transmission includes a first clutch, a second clutch, and a belt coupled to the first and second clutches. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The vehicle further includes at least one controller configured to control a position of the first clutch of the continuously variable transmission in a manual mode of operation. The vehicle further includes a shift request device in communication with the at least one controller. In the manual mode of operation, the first clutch of the continuously variable transmission is shifted by the at least one controller between a plurality of discrete fixed positions based on shift requests initiated with the shift request device. The vehicle further includes an operator input device in communication with the at least one controller. The at least one controller is operative to initiate a torque reduction of the engine during a shift of the first clutch of the continuously variable transmission from an initial fixed position to a target fixed position. At least one of a magnitude and a duration of the torque reduction is adjustable based on the operator input device.
In another exemplary embodiment of the present disclosure, a method of controlling a continuously variable transmission of a vehicle is provided. The vehicle includes an engine operative to drive the continuously variable transmission. The method includes controlling, by transmission control logic, the continuously variable transmission of the vehicle in a manual mode of operation. In the manual mode of operation, a plurality of indicated gears are selectable by the transmission control logic based on shift requests initiated with a shift request device. The plurality of indicated gears correspond to a plurality of fixed gear ratios of the continuously variable transmission and to at least one variable gear ratio of the continuously variable transmission. The method includes receiving a first shift request identifying an initial indicated gear of the plurality of indicated gears. The method further includes varying the gear ratio of the continuously variable transmission across a predetermined range of gear ratios based on the initial indicated gear identified with the first shift request. The method further includes receiving a second shift request identifying a different indicated gear of the plurality of indicated gears. The method further includes controlling the continuously variable transmission to a fixed gear ratio upon receipt of the second shift request based on the different indicated gear identified with the second shift request.
In yet another exemplary embodiment of the present disclosure, a vehicle is provided including a chassis, a ground engaging mechanism configured to support the chassis, an engine supported by the chassis, and a continuously variable transmission driven by the engine. The continuously variable transmission includes a first clutch, a second clutch, and a belt coupled to the first and second clutches. The first clutch is adjustable to modulate a gear ratio of the continuously variable transmission. The vehicle further includes at least one controller configured to control the gear ratio of the continuously variable transmission in a manual mode of operation. The vehicle further includes a shift request device in communication with the at least one controller. In the manual mode of operation, a plurality of indicated gears are selectable by the at least one controller based on shift requests initiated with the shift request device. The plurality of indicated gears correspond to a plurality of fixed gear ratios of the continuously variable transmission and to at least one variable gear ratio of the continuously variable transmission. Upon selection of an initial indicated gear of the plurality of indicated gears, the at least one controller is operative to vary the gear ratio of the continuously variable transmission across a predetermined range of gear ratios. The at least one controller is operative to control the continuously variable transmission to a fixed gear ratio upon receipt of a shift request identifying a different indicated gear of the plurality of indicated gears.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.